Grimlocks are totally blind, but have highly developed senses of smell and hearing. Their sensitive ears and noses combine to allow them to distinguish objects and creatures within 20, just as well as if they were able to see.

Combat: Grimlocks are immune to the effects of spells which affect the vision. These include phantasmal force, darkness, invisibility, mirror image, and many others. However, spells such as audible glamer, or any loud, continuous noise will partially blind them. This reduces their ability to perceive opponents to a 10 range and makes them -2 on their attack rolls. Substances such as snuff or strong perfumes will have much the same effect if inhaled by a grimlock or thrown in its face.

Grimlocks attack fiercely, but with little or no organization, often stopping in the middle of battle to carry off fallen foes or comrades for food. For every 10 grimlocks encountered, there will be a leader of 3 Hit Dice and AC 4, for every 40 there will be a champion of 4 Hit Dice and AC 3. These exceptional individuals will usually be the only ones to show even the most elemental strategy, usually by allowing their followers to weaken opponents before entering battle themselves.

Grimlocks will nearly always attack in darkness if possible. While not adversely affected by light, they are intelligent enough to realize that in total darkness, their unique form of perception gives them a distinct advantage.

Though able to attack with their hands (for 1-6 hp damage), grimlocks prefer edged weapons and will usually (90% chance) be armed as follows: hand-axe, 20%; battle-axe, 15%; two-handed sword, 15%; bastard sword, 15%; broad sword, 15%; long sword, 20%. Leaders or champions will always be armed with a battle-axe or two-handed sword.

Grimlocks, whether normal, leader, or champion, make all saving throws as 6th-level fighters. Grimlocks gain a +1 on surprise rolls, since their acute hearing allows them to communicate in voices too faint for other races to hear. In addition, their morale is raised by 1 for every leader or champion with the group.

Habitat/Society: Grimlocks lair in vast cavern complexes in mountainous areas. They are well adapted to these environs. In any rocky terrain they blend in so well that, while motionless, they are completely undetectable  unless one actually bumps into them. In any grimlock lair, there will be nearly as many females (1 Hit Die and AC 6) as males, and at least as many young (1 hit point, AC 6 and non-combatant). Grimlock leaders and champions do wield some control over these communities.

However, this control is usually effective only as long as the leader who gave the order is around to enforce his will. It is nearly impossible for those of other races to tell one grimlock from another  although leader types may appear slightly larger  but they easily tell each other apart by subtle differences in scent and movement.

Extremely xenophobic, grimlocks rarely consort with other races. However, there is a small (10%) chance that they will allow medusae to share their lairs, and a 2% chance that any wandering group will be accompanied by 1-2 mind flayers.

Ecology: Grimlocks will only eat the raw flesh of humanoid creatures, vastly preferring that of humans to all others. Foraging parties often raid the homes of other subterranean races, especially those who keep large slave populations (such as drow). They are often on good terms with mind flayers since illithids have a large supply of humanoid bodies discarded after they have devoured the brains. Grimlocks are particularly hated by githyanki for this reason. Since the slave flesh the grimlocks often consume (raw) is frequently unwholesome, whole communities are often decimated by disease.